interface IPerson {
  name: string;
  age: number;
}

/**
 *  映射类型
 *   1. 不能使用interface定义
 * */
type MapPerson<T> = {
  // keyof = 'name' | 'age'
  [key in keyof T]: T[key];
};

type NewPerson = MapPerson<IPerson>;

export {};
